Hey there, first off sorry about your breakup, that sucks. He clearly doesn't deserve you. As for the whole looking for a girlfriend situation, I'm in a similar position to you, so I don't really have any advice to add to what Traci and Estelle have said... Put yourself out there, but don't go in with a clear goal. If you're open to a long-distance relationship, I guess you could try out some dating apps/websites although I personally think a relationship is worth much more when you can see your partner in person regularly.
Good luck, and feel free to shoot me a message if you want to chat!
